The scope and limitations of gold-catalyzed tandem cycloisomerization/fluorination reactions of unprotected 2-alkynylanilines to have access to 3,3-difluoro-2-aryl-3H-indoles and 3-fluoro-2-arylindoles are described. An unprecedented aminoauration/oxidation/fluorination cascade reaction of 2-alkynylanilines bearing a linear alkyl group on the terminal triple bond is reported.
The direct functionalization of β-C(sp2)-H bonds in enamides has garnered increasing attention within the realm of organic synthesis. However, these remarkable advancements are predominantly dependent on transition metals; limited success has been achieved via organocatalytic catalysis. Herein, we report a CPA-catalyzed β-C(sp2)-H functionalization of enamides cascade intramolecular cyclization to
烯酰胺中β-C(sp 2 )-H键的直接官能化在有机合成领域引起了越来越多的关注。然而,这些显着的进步主要依赖于过渡金属。通过有机催化取得的成功有限。在此,我们报道了CPA催化的烯酰胺级联分子内环化的β-C(sp 2 )-H功能化,合成了带有偕二氟亚甲基的手性二氢嘧啶并[1,6- a ]吲哚。此外,该方法能够以中等到高产率合成具有出色对映选择性的多种手性二氢嘧啶并[1,6- a ]吲哚。
B(C6F5)3/CPA‐Catalyzed Aza‐Diels–Alder Reaction of 3,3‐Difluoro‐2‐Aryl‐3H‐indoles and Unactivated Dienes
Herein, we describe B(C6F5)3/CPA-catalyzed enantioselective aza-Diels–Alder reaction of 3,3-difluoro-2-Aryl-3H-indoles with unactivated dienes to access chiral 10,10-difluoro-tetrahydropyrido[1,2-a]indoles in good yields with good to excellent ee. The resulting cycloadducts containing an CF2 unit could be further transformed into other important building blocks.
在此,我们描述了 B(C 6 F 5 ) 3/ CPA 催化的 3,3-二氟-2-芳基-3 H-吲哚与未活化的二烯的对映选择性氮杂-狄尔斯-阿尔德反应,得到手性 10,10-二氟-四氢吡啶并[1,2- a ]吲哚的产率良好,ee 良好至优异。所得的含有CF 2单元的环加合物可以进一步转化为其他重要的结构单元。
A tandem gold(I)-catalyzed aminocylization/fluorination and a two-step, one-pot gold(III)-catalyzed cyclization/electrophilic fluorination provide a convenient and general method for the synthesis of 3,3-difluoro-2-substituted-3H-indoles in good yield under mild conditions. Extension of the procedure to the synthesis of 2-aryl-3-fluoro-1H-indoles is described. The reaction proceeds smoothly in green ethanol and does not require any base, acid, or N-protective group.